Board Thread:Pokémon Help/@comment-30108520-20170818184311/@comment-30804097-20170819041059

252+252=504

510-504=6

That was the 6 EVs they were talking about.

The EV system is the same as in the core series, they were just confused since you said 2 EVs, and they didn't put 2 and 2 together to get that you were talking about the 2 extra EVs that are trash.